The burning of fossil fuels produces a tremendous amount of greenhouse gases and wastes that contribute to global warming, bringing a serious environmental crisis to bear upon mankind. Given this situation, there is a pressing need for the development of new, environmentally friendly bioprocesses that uses biomass as fuel, as an alternative to the chemical processes based on fossil fuels to minimize the production of detrimental wastes and the consumption of non-renewable energy. In recent years, there has been a great increase in interest in various bioenergy sources including bioethanol, biodiesel, biogas, and butanol. Some of the kinds of bioenergy sources can be used as fuels for electricity production or transportation, but have drawbacks because of their applicability and production. Now, attention is turning to renewable hydrocarbon compounds, with a concomitant increase of interest in recombinant strains capable of producing long chain fatty acids as their products.
Pseudomonas aeruginosa was first obtained in a pure culture by Gessard in 1882 from cutaneous wounds which had a blue green discoloration. This bacterial species is widely found in nature and frequently isolated from pus, phlegm, excreta, urine, bile, uterine secretions, blood, and spinal fluid. Pseudomonas aeruginosa is a Gram-negative, rod-shaped bacterium that forms a mucous layer composed of extracellular polysaccharides, similar to capsules. This bacterium has great adaptability to any environment, with very simple auxotrophic requirements for growth. Streptococcus pyogenes is a spherical, Gram-positive bacterium that is the cause of many important human diseases, including pneumonia, pharyngitis, acute nephritis, and toxic shock syndrome.
A fatty acid is a monovalent carboxylic acid (—COOH) with a long hydrocarbon chain. Fatty acids are so named because they are produced by the hydrolysis of lipids. In the backbone of a fatty acid, hydrogen atoms are linked to each carbon atom, with a carboxyl group at one end. Fatty acids are degraded or synthesized in vivo through the fatty acid cycle. Most naturally occurring fatty acids have a chain composed of an even number of carbon atoms because the carbons are cleaved from or added to the hydrocarbon chain of the fatty acid in two-carbon atom groups.

In microorganisms, the biosynthesis of fatty acids from sugar starts with acetyl-CoA. Then, the chain is lengthened with the addition of a two-carbon atom unit per cycle to the growing hydrocarbon chain. In the cytoplasm, acetyl-CoA is carboxylated into malonyl-CoA which acts as an important mediator in fatty acid biosynthesis. This irreversible carboxylation is catalyzed by acetyl-CoA carboxylase. The enzyme is composed of three enzymatic subunits and requires biotin and Mn2+ as a cofactor with the supply of ATP during the carboxylation. Two of the three carbon atoms in the malonyl moiety of malonyl-CoA are added to the growing fatty acid chain per cycle of the biosynthesis. Like the production of malonyl-CoA, this reaction is carried out in the cytoplasm by a multi-enzyme protein which is not bound to the membrane. This multi-enzyme protein composed of individual functional enzymes is named fatty acid synthase. The acyl carrier protein (ACP) is an important component of the fatty acid synthase, with the growing chain bound thereto during synthesis.
Incessant trials and effort have been made to overexpress fatty acids in microbes using microbial fatty acid metabolism pathways. Information about the metabolism of E. coli is much more abundant, compared to other microbial organisms. In fact, E. coli is widely used for the production of recombinant proteins because all of its genes have been identified and analyzed. However, not much research has been conducted into the effect of the expression of exogenous genes from other species in Pseudomonas aeruginosa. 
Many studies have been done into improving the production of fatty acids by the introduction of plant genes into E. coli, but genes from other microbial species have not been studied very much for improving fatty acid production, as is done the case for the present invention.
Thus, the present inventors introduced a gene from Pseudomonas, which is rich in lipids including fatty acids, and a gene from a Gram-positive species, which is novel to Pseudomonas, into Pseudomonas, so as to produce fatty acids at greater efficiency.
In the present invention, gene manipulation was carried out, on the basis of the complete understanding of the biological metabolism networks of Pseudomonas aeruginosa, to create a novel recombinant species which can produce a desired metabolite with high efficiency in an early step of the fatty acid biosynthesis pathway.
Culminating in the present invention, intensive and thorough research into the stable and effective production of fatty acids by gene manipulation, conducted by the present inventors, resulted in the finding that when transformed with a nucleotide sequence coding for acetyl-CoA carboxylase carboxytransferase subunit alpha of Pseudomonas aeruginosa and/or a nucleotide sequence coding for malonyl-CoA-[acyl-carrier-protein] transacylase, and a nucleotide sequence coding for acyl-acyl carrier protein thioesterase of Streptococcus pyogenes, Pseudomonas aeruginosa can overexpress the enzymes involved in the fatty acid biosynthesis pathway to activate the pathway, thus producing fatty acids in high yield.